1. Field of the Invention
The present invention relates generally to optical fibers, and particularly to bend insensitive optical fibers comprising a low index of refraction ring therein.
2. Technical Background
Glass optical fibers with improved bend loss properties have recently been of significant interest in the telecommunications field. Techniques for improving fiber bending properties can play important roles in many types of fibers, including transmission fibers used in long distance, single-mode and multimode fibers used in the emerging area of fiber to the home applications, and dispersion compensation fibers where bending loss has limited many designs from practical use. In certain applications such as fiber to the home applications, the ability to form a tight bending diameter of 20 mm or less is desired with negligible bending loss. Many of the proposed solutions for this problem involve significant modification of the fiber refractive index profile.